Odor identification deficits characterize Alzheimer’s disease and other dementias
..Smell Identification Test, which includes the 12-item Brief Smell Identification Test (B-SIT)
..In covariate-adjusted survival analyses, impairment on the Blessed Orientation Memory Concentration Test and B-SIT each predicted dementia (n = 109), primarily Alzheimer’s disease (n = 101). Among participants with intact olfactory (B-SIT ≥ 11/12 correct) and cognitive (Blessed Orientation Memory Concentration Test ≤ 5/28 incorrect) ability, 3.4% (4/117) transitioned to dementia during follow-up with no transitions in the 70–75 and 81–83 years age group quartiles.
Odor identification testing adds value to global cognitive testing, and together can identify individuals who rarely transition to dementia, thereby avoiding unnecessary diagnostic investigation.
•Olfactory and cognitive impairment each predict dementia.
•Impaired odor identification predicts cognitive decline.
•Intact olfaction and global cognition indicates lack of transition to dementia.